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Macchi et al.

entombed at the Saint Anthony Basilica in Padova. In
XVIII century his tomb was demolished for the purposes of restoration of the church, and his remains
were placed in the tomb of his friend Melchiorre Guilandino (Belloni Speciale, 1994; Fig. 1b).
Falloppius stressed the need for instructors of anatomy to utilize a methodology that emphasized direct
observation (“quoniam former sense hoc east cognoscendum not autem ex ratione”), and he highlighted
the differences between his observations of anatomic
structures and those reported in textbooks by Galen
and Vesalius. In 1557, Falloppius began writing the
textbook “Observationes Anatomicae” . He attempted
to elucidate anatomic development by studying
fetuses, infants, children, and adults, introducing the
method of developmental anatomy and embryology.
This method was then developed by two of his most
famous students, Hieronymus Fabricius ab Aquapendente and Volcher Koyter. In particular, Aquapendente
starting from the dissection and anatomy of a structure, describes then its independent action, and its
interdependent function in the body (Smith et al.,
2004).
Unlike many of his contemporaries, Falloppius did
not include illustrations of anatomic structures in
Observationes Anatomicae, published in Venice in
1561 (Fig. 1a), in which the numerous discoveries,
that Falloppius made, are noted. This book consisted
mainly of corrections to and commentaries on Vesalius’s Fabrica (Kothary and Kothary, 1975). Albrecht
van Haller states that Falloppius, in his controversy
with Vesalius, was generally on the right side (Wells,
1948). Falloppius made more discoveries than
Vesalius did, and Falloppius’s research is considered
more precise than that of Vesalius (Ongaro, 2001),
nie de l’invention; Ve
sale, le ge
enie
“Fallope avait le ge
thode; ou pluto
^ t Fallope avait du ge
nie,
de la me
sale n’avait que du savoir’” (Daremberg, 1870).
Ve
In addition to the fallopian tubes, the following
structures bear Falloppius’s name: the opening in the
petrosal bone through which the greater superficial
petrosal nerve passes (falloppian hiatus), and the
small canal in the petrous portion of the temporal
bone through which the facial nerve passes

(falloppean canal or aqueduct). Moreover, he
described an obstetrical anomaly in which implantation of the embryo occurs in one of the fallopian tubes
(falloppian gestation or tubal pregnancy). Falloppius
was the first scholar in the Modern Age to develop the
concept of tissues, which he referred to as “partes
similares,” and the first to state that muscle is made
of connective tissue (Table 1; Tosoni, 1844; Wells,
1948; Speert, 1955; Kothary and Kothary, 1975;
Ongaro, 2001; Mortazavi et al., 2012; Porzionato
et al., 2012).
The facial canal, or fallopean canal, runs across the
medial wall and down the posterior wall of the tympanic cavity to the stylomastoid foramen (Proctor,
1989). The canal of the facial nerve is located inside
the temporal pyramid, and is classically divided into
three segments that are separated by the genu. The
first, or labyrinthine segment, is horizontal, is directed
in an anterior direction, extends from the internal
auditory canal, and is located perpendicular to the
axis of the pyramid; then, it bends sharply going parallel to the greater axis of the pyramid to become the
second or tympanic portion, and then bends a second
time to become vertical until it emerges at the stylomastoid foramen as the third or mastoid portion
(Proctor, 1989) (Figs. 1c and 1d).
While the facial nerve runs in its canal, three
branches, which are the greater petrosal nerve, stapedius nerve, and chorda tympani, exit from the main
trunk. Consequently, the number of nerve fibers
decreases as the nerve approaches the canal exit and
the width of the facial nerve on the distal end is sig€ der, 1994). The main crossnificantly smaller (Schro
sectional area of the exit of the facial canal is wider
compared to the entrance (Dawidowsky et al., 2011),
which Falloppius himself reports (Figs. 1c and 1d).
The size of the facial canal is an important factor in
Bell’s palsy, which is the most common cause of peripheral paralysis in the world. It results from acute
damage to the facial nerve. Several hypothesis concerning its etiology have been proposed, such as
ischemic neuropathy, infection, and genetic and
immunologic causes. Edema of the facial nerve plays
a role in the pathophysiology of Bell’s palsy

Fig. 1. (A) The frontispiece of the textbook
“Observationes Anatomicae” published in 1561 in Venice.
(B) The tomb of Falloppius in the Saint Anthony Basilica.
(C,D) Original description of facial canal at page 27 and
28 of Observationes anatomicae, in which one reads “the
third thing, that I think worthy of attention, is a bony
canal [canalis n. facialis] that runs almost below this cavity [n.d.t. coclear cavity] and exits from the skull behind
the ear burls, more precisely between that and the mastoid process [foramen stylomastoideum]. It begins in the
cranial cavity; if you look closely, you’ll see the fifth pair
of nerves, named this way from other anatomists, extend
almost to the middle of the process of the temporal bone,
which we call internal or petrosal; expanding in this direction, this pair of nerves enters a channel into the bone
[meatus acusticus internus] and inside of it, it divides into

two branches, a big [n. vestibulocochlearis] and a small
very thin and hard one [n. facialis]. This posterior branch,
pierces the bone, flows in the direction of the front of the
head by a hidden channel, then reflects back, enters the
tympanum and, thanks to its own bony canal, goes down
and back, to the root of the wing ear, spreading as I will
describe later. The path followed by this nerve is the channel I’m talking about, which I call by similarity ‘aqueduct’
and which the other anatomists, in my opinion, do not
know well, since they describe it as tortuous, or as a
goat’s horn, or sometimes spiral, calling also, what is
worse, blind meatus, not without error, because they
should know that a part of the intestine is called ‘blind’ in
that it has an input and not an output. This channel
instead has an outlet hole, which is more evident than
that of the input”.